1.Idle Adjustment

This section provides supplemental idle adjustment information to Service Manual TP30421, and should be used in conjunction with this manual.
Check Intake System

- all hoses and hose connections

- air valve for CIS system. The arrow should point towards the cold start injector



Check Ground Wires At Inlet Manifold

If necessary, replace early type connectors (blade type) with later type (eyelet type).

Check CO Setting And Balance

Connect CO/HC meter


Use Gauge Connector (9995151-9)



IMPORTANT

Check 9995151-9 for leakage, as leaks will give incorrect readings on the test instrument.

Check the following before CO adjustment (See 760 Service Manual)

- air fuel control unit sensor plate rest position (PG2:113 Steps Y9- Y11)

- ignition timing (PG3:63 H15)


Warm up engine to operating temperature with AC off.

Remove oil filler cap.



Check CO setting

Specification is 0.8% +/- 0.3 with the oil filler cap removed, and the Lambda sensor disconnected.

If not within specification, adjust CO according to Service Manual TP30421, PG 2:78 N5-N12

NOTE: WHEN THE OIL FILLER CAP IS INSTALLED, THE CO CANNOT RISE ABOVE 1.3%. IF IT DOES, CHECK FOR OIL DILUTION



CO Balance Check

NOTE: Left side of intake manifold goes to right bank, and right side to left bank.

Specification tolerances when checking

The difference between left and right must not be more than 0.5% CO or no side leaner than 0.5% CO.

If not within specification, the engine should be balanced.



CO-Balance Procedure

Air adjusting screw (1) permits a certain quantity of air to bypass the throttle valves at idle. This air quantity is split between the cylinder banks by screws (2) and (3). Screw (2) for right bank cylinders and screw (3) for left bank cylinders. Balance flow by adjusting the appropriate screw, 2 and/or 3.



DO NOT MOVE SCREW (1)


Balance Screws (2 and 3)

Remove the balance screws by drilling and use of an "easy out".


CAUTION: Do not damage the throttle housing nor allow metal pieces to fall into the inlet manifold.



Install New Balance Screws

Screw P/N 269835-5 (2 pieces) O-ring P/N 947114-5 (2 pieces)



Basic Setting

Turn all balance screws to the bottom position (clockwise). Unscrew balance screws 2 and 3 the following amounts:

- balance screw (2) 1 turn
- balance screw (3) 5 turns
- DO NOT TURN SCREW (1)


NOTE: The balance screws on vehicles from late MY 1984 are pre-set in production to 1 and 5 turns respectively.



Check/Adjust Basic Idle Speed

Disconnect link rod from throttle pulley. Ensure that the pulley moves smoothly and does not bind.

Warm up engine to operating temperature with AC off.






Ground the test point for the CIS system.

Test point located at firewall on MY 1983, on right hand wheel housing on MY 1984 and later (as illustrated).



Basic setting throttle plate

Do not touch screw (1). Should remain in bottom position.

Remove the orange wire from micro switch.

- adjust engine speed to 650 rpm by turning the lower adjustment screw on the throttle plate lever.

- adjust adjustment screw for micro switch.

- then adjust speed to 750 rpm with screw (1)



Remove the ground wire from the test pick-up.

Reconnect the orange wire at the micro switch.


Specification:

Engine speed with AC off is 750 rpm.



Check COBalance

Remove oil filler cap and disconnect the Lambda Sensor.



Specification:

The difference between left and right side must not be more than 0.5% CO. No side leaner than 0.5% CO.

If not within specification, adjust to specification with balance screws 2 and 3.









Check HC-Level



Reconnect the wire to Lambda Sensor.


Seal Fuel Control Unit

Install steel ball with sealing tool 9995232-7. Tap ball into position.